Major tech companies like Apple, Google, Yahoo, and Microsoft have transformed from simple transport layers into active intermediaries that parse, rank, summarize, and increasingly respond to communications on users' behalf. This shift began with email and has now extended to push notifications, where Apple and Google control the only two pipes that matter. What started as a battery optimization solution has evolved into sophisticated on-device editing systems that filter, reorder, and rewrite notifications before users see them. The platforms defend user attention as a scarce resource they own, using machine learning models to make opaque, unappealable decisions about what content reaches users, similar to how email spam filters evolved but with even less sender visibility or control.